In-ear headphone



FIG. 1 is a perspective exploded view of an in-ear headphone showing our new design;

FIG. 2 is a side elevational view thereof; and,

FIG. 3 is an opposite side elevational view thereof.

The broken lines showing the environment in the Figures are for illustrative purposes only and form no part of the claimed design.

The rear portion of the in-ear headphone which is not visible in the figures, has been intentionally omitted and is not a part of the claimed design. 

The ornamental design for an in-ear headphone, as shown and described. 